Self-tightening clamp



Sept. 15, 1959 L. D. HAGENBOOK ETAL SELF-TIGHTENING CLAMP Filed NOV. 23, 1956 INVENTOR. Loy D. Hagenbook Roy AKopeik'm W ATgRNEY United States Patent SELF-TIGHTENING CLAMIP L'oy D. Hagenboolr and Roy A. Kopeikin, Chicago, Ill.,

assignors to Goodman Manufacturing Company, Chicago, 111., a corporation of Illinois Application November 23, 1956, Serial No. 624,065

7 Claims. (Cl. 24-426) This invention relates to an improved clamp for connection to a wire rope and more specifically to an auto matically self tightening clamp for attaching elements of a conveyor to a wire rope where the rope forms a part of the structural frame of the conveyor.

It is extremely important that certain elements of a conveyor structure bear a fixed relation to other elements; for example, the supporting rollers for the conveying reach of a belt should be installed in a position which tends to keep the conveying reach running true along a straight line. When the correct position for the supporting roller is established it should be secured to prevent accidental misalignment. In rope frame conveyors, sets of supporting rollers are ordinarily suspended between a pair of parallel ropes and one end of the roller set is moved along the rope to effect proper alignment. The two ends of the roller set are then clamped to prevent further accidental movement.

Devices of the prior art usually employ a type of clamp in which the rope is gripped by the action of a wedge or screw. Both screws and wedges are subject to the objection that they become loose under continued vibration after which the roller set is free to move along the rope. The present clamp is of such construction that in addition to initially gripping the rope, the clamp grips more tightly when there is a tendency toward relative motion between the clamp body and the rope.

Therefore it is a principal object of the present invention to provide an automatically self-tightening clamp connection to the wire rope of a rope frame conveyor.

Other objects and advantages will appear from time to time as the following description proceeds.

In the drawings:

Fig. 1 is a perspective view of a rope frame conveyor showing an improved clamp according to the present invention in association therewith;

Fig. 2 is an elevation view of the clamp looking in the direction of the arrows 2-2 of Fig. 1, showing the clamp in position to secure a set of supporting rollers to a wire rope;

Fig. 3 is a sectional view taken along the line 33 of Fig. 2 looking in the direction of the arrows;

Fig. 4 is a plan view of a stamping which can be formed into the body of the clamp shown in Figs. 2 and 3;

Fig. 5 is an elevational view looking in the direction of the arrows 55 of Fig. 1, showing the clamp adapted to secure a rope spreader to the wire ropes; and

Fig. 6 is a view taken substantially along lines 6-6 of Fig. 1 showing the clamp adapted to secure the rope to a supporting stand.

Referring to the details of the embodiment of our invention illustrated in the drawings, there is shown a rope frame conveyor generally indicated by the numeral 10 and consisting of a conveying reach of belt 11 supported on a set of rollers 13 which is suspended between a pair of ropes 14 and 16. The ropes 14 and 16 are supported on a stand made up of upright legs 17 resting upon feet 19 and spaced apart by a spacer 18. Feet 19 have upice turned flanges 21 upon which is mounted a roller 22 for supporting a return reach 12 of the belt 11. At the top of each upright leg 17 is a U-shaped clamp body or saddle 23 embracing and supporting the ropes 16 or 14 as the case may be.

A spreader 24 rests upon the ropes 14 and 16 tomaintain proper spacing of the ropes. Each end of the spreader has an inverted U-shaper clamp body 26 which engages the rope. Between the spreader 24 and the rope support stand there is a pair of the roller sets 13 each made up of a center roller 27 and a pair of wing rollers 28 mounted. to turn upon dead shafts 29. The shafts 29 are connected to each other in such a fashion that the rollers 27 and 28 can freely swivel in a vertical plane such as is shown in Craggs et al Patent No. 2,773,257, issued December 4. 1956, for Conveyor Having Flexible Strand Side Frames.

The outer end of each shaft 29 is connected to a pair of shackles 32 by a pin 42 and the shackles 32 in turn are connected to a U-shaped clamp 33 by a pin 39. Washers 41 are provided to space out the shackles 32 inasmuch as the shaft 29 is thicker than the leg 37 of the clamp 33.

As seen in Fig. 4, the clamp 33 may be formed from a blank generally in the form of a hollow rectangle with end portions 36 and 37 continuous with side portions 38. The blank is bent to the U-shaped configuration seen in Fig. 2 with the portions 38 forming a pair of spaced arcuate shaped abutments which define abutment surfaces that face in a common direction that is generally laterally of the rope 16 and engage against longitudinally spaced portions thereof, note Fig. 3. As seen in Fig. 2 end portions 36 and 37 of the blank shown in Fig. 4 become upper and lower legs 36 and 37, the lower leg 37 providing a point of attachment for the wing roller 28 seen in Fig. 2.

The inner edge of each end portion 36 and 37 defines bearing means that is serrated respectively as at 34 and 34a, to define bearing surfaces which are disposed intermediate the spaced abutments defined by the portions 38 and in longitudinally spaced relationship thereto relative to the longitudinal axis of the rope 16 with the serrated bearing surfaces 34 and 34a facing in a direction that is opposed to the direction which the abutment surfaces face. The serrated bearing surfaces 34 and 34a match serrations 47 of a pin 43 having a shouldered head 44 and a tapered end 46. The serrations 47 of the pin 43 are arranged to cooperate with the wire rope 16 as seen in Fig. 3. The rope 16 is of a type called Lang lay in which wires 53 thereof are wound in the same direction as strands 52 thereof, so that the wires 53 are oblique to the longitudinal axis of the rope. These individual wires 53 form a surface of alternate lands and grooves which can be engaged by the serrations 47 of pin 43.

The operation of the clamp will be described in terms of the embodiment shown in Figs. 2 and 3 inasmuch as they also illustrate the embodiments shown in Figs. 5 and 6. The clamp 33 is hooked over the rope 16 so that the abutments 38 embrace the rope 16 and is moved along the rope to give the desired alignment of the roller set 13. The tapered end 46 of pin 43 is inserted between the rope 16 and the serrated surfaces 34 and 34a of the clamp body 33. The serrations 47 of pin 43 will engage the serrations of bearing surfaces 34 and 34a and the wires 53 of the rope 16 in such a fashion that the pin 43 will tend to rotate as it is driven down. However, the rope 16 and clamp body 33 maintain the same relativepositions with respect to each other as they had before. As shown particularly in Fig. 3, insertion of the pin 43 will cause the rope 16 to bulge between the spaced abutments 38 such that the axis of that portion of rope between abutments 38 is inclined with respect to the bear ing surfaces 34 and 34a.

The serrations of the bearing surfaces 34 and 34a and the serrations 47 of pin 43 together with the wires 53 of rope 16 cooperate to rotate the pin analogous to a pair of racks, one on either side of a pinion. Thus when the clamp 33 tends to move relative to the rope 16, the pin 43 tends to roll along bearing surfaces 34 and 34a. Because of the inclination of the rope axis between the abutments 38, the pin 43 would be required to roll into a space having a width which is less than the diameter of the pin, the width becoming smaller as the pin moves toward the abutment 38. The pin thus deflects the rope 16 as it rolls to increase the pressure of the rope against the nearest abutment, thereby increasing the frictional holding force between the rope 16 and the abutment 38. It will be seen that any tendency of the clamp 33 to move along the wire 16 will be opposed by reason of the rolling action of the pin 43, and the consequent increased wedging action against .the cable 16.

While the serrations provide positive driving engage- I ment between the pin, rope, and bearing surfaces in applications where very little relative movement between clamp and rope is permissible, there are other applications in which a smooth pin can be used with smooth bearing surfaces and regular lay rope.

Although we have shown and described a preferred embodiment of our invention, it will be understood that we do not wish to be limited to the exact construction shown and described, and that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

We claim as our invention:

1. A self-tightening clamp for forming a connection to a rope or the like that is subjected to movements in a direction that is generally longitudinal thereof, said clamp being substantially U-shaped in configuration having an open portion for passing such rope therethrough to position the clamp thereon and a closed portion laterally spaced from the open portion relative to such rope, said closed portion defining a pair of spaced abutment surfaces facing in a common given direction that is generally lateral of such rope for engaging longitudinally spaced portions thereof, elongated bearing means disposed adjacent the open portion and facing in a direction opposed to said given direction, said bearing means extending generally longitudinally of such rope in laterally spaced relationship to and longitudinally intermediate of said abutment surfaces, and an elongated locking member interposed between and in engagement with the bearing means and that part of such rope that is intermediate the spaced portions thereof which are engaged by the abutment surfaces, said locking member being intermediate of and normally spaced from each of the abutment surfaces and moveable along the bearing means in substantially the same direction that such rope moves, whereby on movement of such rope the intermediate part thereof will be deflected in a generally lateral direction to increase pressure between such rope and the abutment surface that is normally spaced from the locking member in the direction which such rope moves to thereby further tighten the connection.

2. The self-tightening clamp as set forth in claim 1 wherein said elongated bearing means comprises a pair of generally parallel bearing surfaces defined by the end portions of the U-shaped clamp.

3. The self-tightening clamp as set forth in claim 1 wherein said locking member comprises a pin substantially circular in cross-section rollably engaging the hearing means.

4. The self-tightening clamp as set forth in claim 1 wherein said bearing means and the locking member are provided with intermeshing teeth.

5. A self-tightening device for suspending an elongated conveyor component between designated locations on a pair of laterally spaced flexible strands of a flexible side- 4 frame conveyor to retain such conveyor component secured thereto at the designated locations thereon during movement thereof, said device including a clamp carried by each end portion of the elongated conveyor component, each of said clamps being substantially U-shape in configuration having an open portion for passing the respective strand therethrough to position the clamp at the designated location thereon, a closed portion laterally spaced from the open portion relative to the respective strand, said closed portion defining a pair of spaced abutment surfaces facing in a common given direction that is generally lateral of the respective strand for engaging longitudinally spaced portions thereof, elongated bearing means disposed adjacent the open portion of said clamp and facing in a direction opposed to said given direction, said bearing means extending generally longitudinally of the respective strand in laterally spaced relationship to and longitudinally intermediate of said abutment surfaces, and an elongated locking member interposed between and in engagement with the bearing means and that part of the respective strand that is intermediate the spaced portions thereof which are engaged by the abutment surfaces, said locking member being intermediate of and normally spaced from each of the abutment surfaces and movable along the bearing means in substantially the same direction that the respective strand moves, whereby on movement of the respective strand the intermediate part thereof will be deflected in a generally lateral direction to increase pressure between the respective strand and the abutment surface that is normally spaced from the locking member in the direction which the respective strand moves to thereby further tighten the connection.

6. A self-tightening device for suspending an elongated conveyor component between designated locations on a pair of laterally spaced flexible strands of a flexible sideframe conveyor to retain such conveyor component secured thereto at the designated locations thereon during movement thereof, said device including a clamp carried by each end portion of the elongated conveyor component, each of said clamps being substantially U-shape in configuration having an open portion for passing the respective strand therethrough to position the clamp thereon, a closed portion laterally spaced from the open portion relative to the respective strand, said closed portion defining a pair of spaced abutment surfaces facing in a common given direction that is generally lateral of the respective strand for engaging longitudinally spaced portions thereof, elongated bearing means including a bearing surface having teeth thereon disposed adjacent the open portion and facing in a direction opposed to said given direction, said bearing surface extending generally longitudinally of the respective strand in laterally spaced relationship to and longitudinally intermediate of said abutment surfaces, and an elongated substantially circular locking pin having teeth thereon interposed between and in engagement with the teeth on the bearing surface and that part of the respective strand that is intermediate the spaced portions thereof which are engaged by the abutment surfaces, said locking pin being intermediate of and normally spaced from each of the abutment surfaces and rollably movable along the bearing surface in substantially the same direction that the respective strand moves, whereby on movement of the respective strand the intermediate part thereof will be deflected in a generally lateral direction to increase pressure between the respective strand and the abutment surface that is normally spaced from the locking pin in the direction which the respective strand moves to thereby further tighten the connection.

7. In a self-tightening clamp connection, a stranded wire rope that is subjected to movements in a direction that is generally longitudinal thereof, said rope having the wires of the strands twisted in a direction generally lateral relative to the longitudinal axis of the rope, a clamp of substantially U-shape configuration having an open portion for passing the rope therethrough to position the clamp thereon, a closed portion laterally spaced from the open portion relative to the rope, said closed portion defining a pair of spaced abutment surfaces facing in a common given direction that is generally lateral of the rope for engaging longitudinally spaced portions thereof, elongated bearing means including a bearing surface having serrations thereon disposed adjacent the open portion and facing in a direction opposed to said given direction, said bearing surface extending generally longitudinally of the rope in laterally spaced relationship to and longitudinally intermediate of said abutment surfaces, and an elongated substantially circular locking pin having serrations thereon interposed between and in engagement with the serrations on the bearing surface and the twisted Wires of the strands of that part of the rope that is intermediate the spaced portions thereof which are engaged by the abutment surfaces, said locking pin being intermediate of and normally spaced from each of the abutment surfaces and rollably movable along the bearing surface in substantially the same direction that the rope moves, whereby on movement of the rope the intermediate part thereof will be deflected in a generally lateral direction to increase pressure between the rope and the abutment surface that is normally spaced from the locking pin in the direction which the rope moves to thereby further tighten the connection.

References Cited in the file of this patent UNITED STATES PATENTS 

